For some reason people have this idea that LNG tankers are a big bomb waiting to go up, but that's not really true. Vapor cloud detonation has never been considered particularly likely, and never documented as far as I know. Mostly it seems the vapors that hit the right mix of oxygen and such would burn pretty rapidly, while the warmer gas began to rise. It would certainly be a large fire for a while, but shouldn't have the lasting impact of an oil spill. Here's a paper[1].
The scary bit for LNG is a BLEVE (Boiling liquid expanding vapor explosion). Even non-flammable liquids undergoing a BLEVE can be incredibly destructive, for example:
https://www.youtube.com/watch?v=fgdfgxLApL4
So it's nothing to do with vapor cloud detonation, that's pretty much irrelevant compared to the destruction of the rapid phase transition from liquid to gas.
I think a tanker ship is pretty safe from a BLEVE. Those explosions usually result from a tank being heated continuously by a very hot fire underneath it. I'm not sure where you would find one of those at sea unless the tanker wrecked on top of an erupting volcano.
How about an LNG bunkering facility in Naples, near the Campi Flegrei volcano?
Maybe you start with a minor eruption/earthquake, and the LNG disaster breaches a larger magma chamber to cause a larger eruption? Then you can blanket Europe in ash and start up the typical disaster movie plot, where you follow the Chicken Little and their family as they try to escape the disaster radius.
If you are suggesting that a nuclear power plant can detonate like a nuclear bomb, you are wrong, they are a completely different design. Sure they can melt down in rare cases, but that's hardly anything on the scale of a nuke. I would suggest you look at some of the stats for death rates of different power sources. Nuclear is near the bottom, coal kills thousands every year through air pollution. If you want to find a truly dangerous power source, look at hydroelectric, when a dam collapses it is more damaging than a power plant meltdown in some cases.
I wonder how thoroughly the various failure scenarios have been modeled and reported on. Something merely of the magnitude of the East Ohio Gas Fire [1] in a crowded port or canal would be awful, and I'm pretty sure a supertanker carries a lot more gas.
The industry has every incentive to do a careful job with the safety features of these ships and the terminals they unload into, but the trouble with ships is that things sometimes run into them... sometimes really big things.
It's a pretty awesome way to carry around a lot of portable energy, though.
That was a salt dome holding area, and not a tanker, to be fair.. but yes, it exploded. People in houston (~45m-1h drive away) felt the rumble and thought it was an earthquake..
> Vapor cloud detonation has never been considered particularly likely, and never documented as far as I know
This is an example of a vapor cloud detonation. I'm just pointing out that it's happened, so I'm not sure why you're saying it's never been documented. Unless you just meant in the context of a tanker, but that's not how you phrased it.
As it happened, I lived in the area at the time (about 40 miles away on the back side of Cypress, Texas). I didn't think so much about it being an earthquake, but instead thought a large airplane had crashed nearby. I ran out into the street expecting to see fire and explosions and whatnot within a block or few of my house ... only for there to be _nothing._
x2. Explosives that used ambient oxygen to burn the fuel need to be finely tuned. Blowing up a propane tank (regardless of size) gets you a big fireball.
I find the fear of flammable gasses to be irrationally excessive. Sure there's more stored potential energy than the batteries under the floor of your Prius or the smartphone in your pocket but by nature of being compressed the storage tank is very robust and unlike batteries they do not include their own ignition source.
"Mini-nuke" isn't a very accurate comparison. In the event of a leak, the liquid fuel would need to flow out of the tank and turn into vapor before it could catch fire and burn. As a liquid or highly concentrated vapor it's not flammable. It needs to mix with air first.
The result would be a cloud of gas that burns violently for several minutes, depending upon wind and the speed of the leak. Not the instantaneous, crater-making release of energy that a thermonuclear device produces.
If you suddenly removed the top of a large container of LNG, it wouldn't all instantly vaporise. It would start to boil, rapidly cooling its surroundings due to the latent heat of vaporisation. Large amounts of ice would form on the outside of the container, and pretty soon the boiling rate would drop off substantially as the rate of heat transfer from the now frigid surroundings reduced.
If the vaporising gas was ignited, some of the heat from that combustion would certainly be transmitted to the pool of cold, liquid gas by radiation which would increase the vaporisation rate. The net result would still be a release of energy into the surroundings over probably tens of minutes (as opposed to microseconds in the case of a nuclear bomb).
You can demonstrate this yourself pretty easily using an ordinary 20-lb barbecue tank, a "high pressure" aka 20 psi regulator ($20 on amazon), and a high-pressure burner head (also $20 on amazon). Turn it all the way up - you'll get a great big hot flame at first, but you'll quickly see a shell of ice forming on the outside of the tank, because the process of evaporation drains heat out of the propane very quickly, and it gets cold enough to condense water out of the atmosphere into ice. Within half an hour, that big hot flame will have died down to something very gentle: the tank is still full of propane, but it's now so cold it'll no longer evaporate quickly enough to keep the pressure up. You'll have to turn it off and let it thaw for a few hours before it'll really get going again.
The LHPO runs only on propane, at full bottle pressure (that is, five to ten bars, depending on ambient temperature).
The LHPO may be run from either a bank of propane bottles feeding into a manifold and then proceeding along a main gas pipe to the organ, or from a single propane tank with either liquid or gas feed. If liquid feed, a gasifier must be provided with sufficient peak capacity (see below).
If a single tank, the tank must have at least a three ton filled capacity, to provide enough thermal mass for the required gas delivery rate (see below). The tank connection must be at least 1 1/2 inch inside pipe diameter, to provide for sufficient gas delivery rate.
If a multiple tank installation, at least 28, 33kg capacity bottles are needed. The bottles may not be all close packed into a rectangular array, but must be in one or two rows, with adequate air circulation around the bottle area to provide for heat transfer to the bottles.
If a liquid phase system and a gasifier are to be used, the system must be able to deliver the peak delivery rate (see below) for at least ten minutes continuously."
Well, the double hulls of these ships are inch-thick steel, but I think the dome is less protected. An attack that blew the dome off could open up a large hole and ignite the escaping gas, but it would still take minutes for all of it to boil off, probably freezing as it does.
I guess a big enough rocket could blow the liquid out of the tank, or rupture a large hole in the hull of the ship causing the LNG to dump into the (relatively) warm water and boil off faster. But at some point the real question is: How did the bad guys fire rockets into a secured unloading station?
Inch thick is the same as road plate and means nothing when there's tens of thousands of tons of ship involved. Freight ships are built as light as possible. Steel that you don't have to float leaves room for more cargo weight and increases fuel economy.
This site has been completely revamped, the graphs look a lot clearer.
I guess this is down to the inclusion of solar power which was cursory a few years back. Do they now aggregate all of the roof top solar and add that in?
Snooping around Glastonbury and my great Aunt's old town I've noticed a number of Solar farms in the countryside:
1 megaton? Even the largest LNG tankers can hold only 67 kilotons, so even if you had a perfect stoichiometric mixture somehow and detonated all of it at one you'd get maybe a 130 kiloton explosion.
There are multiple factors that give rise to natural gas's much greater energy density:
- TNT carries its oxidizer internal to the molecule instead of getting it "free" from air
- TNT equivalent energy does not include full combustion of the oxygen-deficient detonation products, only instantaneous energy release during detonation
- TNT has a lower hydrogen:heavy atom ratio than natural gas
> Modern nuclear bombs are ~20Mt, with the biggest at 100Mt.
IIRC US (and other Western ones as well I guess) ICBM warheads are about 300Kt, Russian ones about 1Mt.
The Russian did test a 50Mt device (Tsar Bomba) during the cold war (technically, there's apparently no upper limit how big you can make them), but such large devices are not really militarily useful to the point of justifying their bulk/weight/expense.
I thought Tsar Bomba was designed to have 100Mt yield, but they dialed it back (by using less fissile material I think) because there was no reason to set on of that large and because of safetey. It was my understanding that the nearby towns wouldn't be threatened by a 50Mt bomb and but a 100Mt was expected to break windows and stuff. Also the time for the pilots to get away was improved.
> Modern nuclear bombs are ~20Mt, with the biggest at 100Mt.
IIRC, the biggest the US ever deployed operationally was 9Mt, and those have since been retired. The common strategic warheads now deployed are, IIRC, 100-350kt range.
LNG tankers are freaking scary though, they are like mini-nukes, approaching 1 megaton equivalent.